Dental flask



p 6, 1932- w. F. RODlN ET AL 3 DENTAL FLASK Filed Dec. 17, 1929 2 Sh eets-Sheet l 32 MLL/AM EEOD/N BY ALEm/wEe H0021.

ATTORNEYS.

p ,1932. w. F. RODIN E1. AL 1,875,660

DENTAL FLA S K Filed Dec. 17, 1929 2 Sheets-Sheet 2 35 c 23 14 I /4- A I INVENTOR5 MLL/AM E Poo/xv A TTORNE YS.

to the cavity incident to the Patented Sept. 6, 1932 WILLIAM F. RODIN AND ALEXANDER RURAL, or LOS cA IFORNIA .DENTAL FLA'SK Application filed December 17, 1929. Serial N 0. 414,862.

Our invention relates to dental curing and vulcanizing flasks, and has for itsprimary object the provision of means for automatically compensating for expansion and contraction of the vulcanizable plate-forming material during the vulcanizing process, whereby to insure accuracy'in the formation of plates, which said means is structurally qualified so as to function topack or condense the molten mass of material in the mold cav ity and thereby maximize the density ofthe material and render same free from voidsiand imperfections that, if left in the finished plate, would result in a weakened plate structure.

In the work of supplyinga dental flask with molten plate-forming material, such as vulcanizable rubber, it frequently happens that either too much or too little of the material is supplied the mold. If the flask isoversupplied, it follows that the mold is liable to fracture when subjected to the customary steps of a vulcanizing treatment, and that, incident to the action of expansion and contraction of the material, the structure of the denture is sometimes so disorganized that same is made wholly unfit for the purpose intended. lV hen material in an 'insuificient quantity is placed in the mold, it consequently results that the teeth to be cast in the plate find insufficient anchorage therein and same can be easily separated from their sockets.

We have designed certain new and novel means whereby conditions within the flaskare always discernible from a point exteriorly of the flask, which said means automatically functions to exert pressure upon the plateforming material and to closely pack same within the mold cavity, while being free-to permit of movement of thematerial relatively action of expanding and contracting temperatures'to which the material is subjected. The means Which we have employed isself-compensa-ting to all internal conditions of the flask and it isfurther designed so that, and should external .eration conducted entirely externally of the flask,1a-nd while the sections of the latter are eXami-nation offthe flask indicate lth'at the under pressureiby theaction ofany customary press. Again, it is afurther aim of the in- V vention to provide means whereby, should the mold cavity be over-supplied with plateforming- ,material, same maybe, bled to the outside of the flask. In other words, apartof the whole mass originally supplied the mold I cavity can =be:quicklyevacuat ed from thecave .ity and in -a way that will enable a skilled operator, or even a laboratory assistant, to ascertain when the cavity is properly supplied in :a way. that will satisfactorily 'meet' those requirements for a strong durable plate structure andran adequate anchorage of the teeth therein. a Q

' Our invention. is usedrpre'ferably inrcom junction with :axflask formed 0f separable sections, and we :have provided in cm assembly- 0f instrumentalities means for preventing the plastic-niateriakwithin theflask from escaping from the flask-by wayrof'the joinde'i' between the flask sectionsfl" In other 'WOIdS, we :have employed herein means for satisfactorily (establishing awperfectseal at the point between'the flask sections so as to prevent extern a1 :pressuresfromentering the flask'while avoiding. an escap'e of materials within the flask by the action of internal pressures, all of which said pressures are due to actionsof heats during the vulcanizing treatments;

Our invention raims further to provide a novel organization of parts including means that will enable'the flask sections to be either set up or taken apart with ease and'dispatch, and means for holding all of the parts in assembly and-firmly pressed togetheri Inlthe accompanying drawings, 1 Fi re l is a perspective view of the flask showlngthe same fullyassembled;

Figure 2 is a perspective view showing the component parts of the flask disassembled;

Figure 3 is a vertical section through the flask on line 3-3 of Figure 1 showing the initial position of the pressure exerting means with respect to the mold cavity.

Figure 4 is a horizontal'section on anengrgied scale through a central portion of the Except for one feature of importance, which we will stress hereinafter, we make no claim to the steps of the molding method employed. The customary plastic material used in connection with dental flasks is applied within the flask sections in the-usual well'kn'own manner.

within the flask also in the usual manner,- so

- that the wax carried thereby will function to 1 customary method of arranging tical recess 11'.

produce a mold cavity in the plasteriof Paris mass contained in the flask. There is to be considered; however, in connection with this a mold within plastic matter in the flask, the fact that our mold sections-are so proportioned and otherwise designed that the mold cavity will occupy a positionwith respect to the flask sections as will enable the same to be operatively correlated to the means for exerting pressure upon the molten plate-forming material. This relationship of the parts will be de scribed in; proper detail as theidescription pro'ceeds. a f f Weemploy a'flask which comprises an upper annular'body 10 having vertical lugs 10, a mating lower annular body 11 having a verrccesscs 11 -4 1 an intermediate annular gasket 12having recesses 12', an imperforate top 13 having recesses 13,

and i an imperforate bottom or base 14: hav

' illustrated in Figure to be built up one upon peripheral edges with Thelowersection 11 is formeclxwith vertiing vertical lugs 14, the latter adapted'lto fit in the mating vertically aligned recesses 12 and 11?. The lugs 1() are adapted to fit if in the aforementioned recesses 13.' All of I above mentioned are relatively ofthe same external and internal diameters so that the flask presents when setup a cylindrical structure whose external walls are perpendicular. The said parts are adapted 7 the other soas to come in close mating contact at the joinders between the respective 'parts. :Thefsaid parts are also preferably formed of brass and, as 2, the aforementioned gasket-12 is open at one side as at 15. The confronting ends'of the gasket are formed with aline'd recesses 16, the purposeof which the parts just a will be'explained hereinafter.

The bottom or base '14- is provided in its vertical. recesses 17.

cal recesses 18 which coincide 'with the re cesses 17 The1gasket112 is formed-with recesses 19 adapted to coincide-with the re cesses-18. Theupper section 10 .isfornied with recesses'20 to coincide withithe recesses The mold is arranged threaded adjusting should now be made to 19, and the top 13 is formed with recesses 21 to coincide with the recesses 20. WVe have now described an arran ement of the respective flask parts whereiy the external recesses of these parts may be brought into coinciding relationship with each other so as to allow for the accommodation therein of equidistantly spaced clamping arms 22 of which there are preferably three. These arms are formed with angularly extending flanges '23 at their lower ends adapted to engage under the bottom section 1% of the flask. The upper ends of these arms are looped about pintles 2 1 which are carried in loops 25 formed upon arms 22 are'constructed of rigid material,

preferably metal, and the clamp head 27 is constructed of resilient metal, so that the extensions 26 of the latter may be put under some e'lastic'strcss. The clamp head 27 is formed at'its center with a threaded aperture 28 adapted to receive an ex ernally plug 29; Reference ings,=wherein it will be observed that the upper extremities of the arms 22 extend above the top section 14 of the flask. Also it will be observed that the plug 29 is freely adjustable in a i acting opening 28I'n the clamp head 27.

- Likewise is it observed that the plug may be adjusted in the opening 28 so that the lower face of the plug can be firmly pressed against the flat upper face of the flask tion 13. The plug 29 is formed with a vertical wrench cavity 30inorder that the plug can be turned either to the leftwhen ciiecting' a clamping action between the flask parts or to the right whenit is desired to knock down the flask. V j v V The gasket 12 projects into the flask cham her and same is formed with avertical rib 31 which is spaced apart from the inner walls of the flask section 10. for the flowing of plaster over the rib so as to produceflanefl'ective plastic key at the joint between the gasket and thesection 10 of the. flask. The upper face of the gasket falls in horizontal alinement with the joint between the two plastic masses contained in the two sections 10 and 11 of'the flask, and these massesmay be isolated from each other through the medium of a suitable'varnish ofthe type customarily em- Nev thev outwardly extend- Figure l of the draw- I verticaldirectlon in its co use.

.This allows,

or seal 7 7 ployed in dental flasks of the character before us. This prevents escape of the plastic material within the flask, and'it alse seals the flask against the action of external pres sure when the flask issubme-rged in hot water during the time ofmelting the was;

. bore.

-, 43 or by the action of plunger-like and with the recess 34 in the flask section 10. The recess 33 formslugs 35 at opposite sides thereof on the saddle 32 and 'these'lugs are received in recesses 35 formed in the section 10. They are also received in recesses 35 inthe gasket 12. The recesses 33 and'34 combine to produce or define a circular receptor for.an:open-ended cylindrical barrel 36. This barrel is formed atits sides with pins 37 adapted to enter the respective recesses 16 in the confronting faces of the gasket .12. The barrel is ofa length whereby it projects well into the flask, as will be seen on reference to Figure4 of the drawings, so that its inner end is in horizontal alinement with the plate-forming cavity A. Within the barrel is a combined pressure exerting or compressing means and vent means B which comprises a body having sections 38 and 39 of respectively different external diameters, each section being a cylinder of suitable length. The said body has a bore 41 which threadedly accommodates a screw plug 41 which normally serves to close said Between the outer wall of thebarrel 36 and the shoulder 42 of the combined pressure exerting and vent means is a spring 43 which functions to normally urge said means B in the direction of the mold cavity A. A stop pin 45 operates in the groove 46 in the means B to limit movements of the latter. In this manner, it follows that said means B cannot be entirely withdrawn from said barrel 38 either by action of the spring pressure created with- At this point, it is stated that exerting and vent means acts same is free for pulsating movement in the barrel in order to accommodate itself to the action of internal pressures. It is, therefore, self-compensatingto all pressure actions that are customarily created in flasks of this nature during vulcanizing of the plate-forming material.

Having described the essential structural characteristics of the flask, a brief description in the flask. the pressure of its mode of functioning will be as follows: Plaster of Paris is placed in the lower flask section 11. The plate-forming mold A is associated with the plastic material. The flask sections are then superposed relatively and t c section 10 filled with plaster in the regular manner. The plaster within the flask is then permitted to harden, after which the flask is subjected to the action of hot water to melt the wax carried by the mold and thereby produce a plate forming cavity within the plastic mass within the flask when the wax is melted out. By isolating the plastic mass contained in the section 11 from the mass contained in the section 10, it follows that after the wax melting step has been conducted the two masses may be freely separated and vulcanizable material, such as rubber or other well known equivalent thereof,

applied within the mold cavity thus produced. When arranging waxin the flask, a slug forming portion G is. interposed between the inner end of the means B and the mold A. Duringthc process of melting the wax so as to produce a mold cavity, in the plaster contained in the flask, it follows that the portion G will .also be melted so as to leave a void between the inner end of the means B and the cavity. The vulcanizable material within the flask is now ready to be subjected to the customary vulcanizing treatment. Due to the characterizing features of the pressure exerting and vent means B, it manifestly follows that when theflask is subjected to the action of vulcanizing heats and the plateforming material is thereby made to respectively expand and contract, the slug C, which normally acted as a barrier, has now been melted away and the said means B is free for reciprocal movement. It is self-compensating to all capacity charges contained in the mold cavity, and should it happen that the mold cavity contains less material than is suitable for a practical manufacturer of a dental plate, this may be ascertained by simply withdrawing the screw 41 B, at which time it will be found that no molten plate-forming material will find egress from the mold cavityby way of the from said means bore 41 in said meansB. This would go to indicatethat the mold cavity. contains an insuflicient quantity of vulcanizable material and the operator would then inject into the way of said bore such quantity as 1 cavity by may prove ample for the. occasion. This operation may be. continued-from timeto time until no .vulcanizable material finds escape to the outside by way of said bore. Here it should be noted that the screw plug 41 is not left permanently disconnected from said means B after an inspection of the internal workings of the flasl. It is intended that on each inspection the screw be again driven to its home.

when the screw is removed should too much material be contained in the mold cavity, the excess is free to flow therefrom, where it will pass off to the external. part of the flask by Conversely, it follows that way of the bore in said means B. We have accordingly devised ways and means whereby an operator can determine accurately the internal workings of the flask during the entire vulcanizing treatment. The plunger-like pressure-exerting and vent means B operates automatically and exerts a normal pressure against themolten plate-forming material."

In this manner, and when the mold is insufiiciently packed, the vulcanizable material in the plate-forming cavity of the mold may be supplied with a further quanity of material. The means described herein is reliable in action and is self-compensating to all ordinary heat pressures, and by permitting the excess of material to seek its escape fromthe mold V spaced relation that would weaken the commercial or finished plate. 7

In order that the plug 29 may be operated to effect a maximum clamping action and at the same time be capable of easy adjustment with little created friction, we provide same with an annular series of anti-friction bodies 29 which are free to ride against the flatface of the aforementioned flask section 13.

We claim as our invention:

1. A flask having an inwardly-extending barrel, a yieldable plunger carried by the barrel and extending into the flask, the plunger having a bore opening into the flask, and removable means for normally sealing the bore at one end. i

V 2. A flask including a plurality of mating flask sections superposed with respect to each other, a gasket removably interposed between said sections and having an annular ribcoccupying a position within the flask and in to the inner surface of one of said sections so that plaster contained in the flask will flow over the rib and onto the gasket at a point between said mating sections, closing means for the flask, and means for clamping the closing means and the flask sections together.

3. A dental flask including a plurality of mating-flask sections, means for clamping the sections together, a yieldable plunger carried by one section and having a bore extending from a point at the exterior of the flask to a point interiorly thereof, and closin means for said bore. I

4:. A dental flask having a bore between its upper and lower ends, the said bore extending from a point at the exterior of the flask to a pointlinteriorly thereof, a plunger operating in the bore, means for normally urging the plunger in one direction, the plunger having a bore therein, and means removable from the hore of said plunger and serving to normally close same against the escape of material from the flask. Y 7

5. A sealinggasket for dental flasks comprising an annular body adapted to be interposed between two flask sections, a cylinder carried by'the gasket and having an open end adapted to be extended into a flask when the gasket is operatively related to said flasksections, and a yieldable plunger operating in said cylinder. 1

6. A sealing gasket for dental flasks comprising an annular body adapted to be interposed between two flask sections, a cylinder carried by the gasket and having an open end adapted to be extended into a flask when the gasket is operatively related to said flask sections, a yieldable plunger operating in said cylinder, the plunger having a threaded bore extending therethrough, and a closing screw normally closing said bore.

WILLIAM F. RODIN. ALEXANDER I'IURAIH 

